[netCDF #NUC-119714]: struggling with writing data to nc file

> Below is the header information of this input file that I read with
> the script. But the reading seems to work all fine. The problems are
> involved in then simply writing out the read data which I want to do
> to be sure that I get the data for the proper location. I will also
> check for these other locations to get the information on the
> netcdf-3 F77 functions.

First, even though the reading "seems to work all fine", it's probably
not doing what you think it is.  In a loop with ii=1,12, you have

         CALL read_nc_file(ii,ncid,emisid,emis)

but the code is just reading the entire 4D co_flux variable, including
data from all 12 times, each time through the loop, with the
statement:

        CALL nf(nf_get_var_real(ncid,emisid,emis)) ! emis.

in the read_nc_file subroutine.  If you really intended to read data
from one time with each call, making use of the value of the "ii"
parameter, you would instead have something like

        start = (/ ii, 1, 1, 1 /)
        count = (/ 1, 6, 180, 360 /)
        CALL nf(nf_get_vara_real(ncid,emisid,start,count, &
                emis(ii, 1, 1, 1))) ! emis.

and each call would read in only the data for the ii-th time and store
that 3D slab of co_flux data in the right place in the 4D emis variable.

Second, I'll assume maybe you already knew all the above and really
just want to figure out what's wrong with the writing.

In your output_netcdf subroutine, the loop for setting the emis_output
array, declared emis_output(ilat,ilon), looks wrong:

          FORALL (I=1:nlon, J=1:ngl)
            emis_output(I,J) = emis(ii,I,J)    
          END FORALL

If the declaration is right, this should instead be

          FORALL (I=1:ilon, J=1:ilat)
            emis_output(I,J) = emis(ii,I,J)    
          END FORALL

unless you pass nlon and ngl as arguments to the subroutine.

In the write_nc_file subroutine, you first write the 1-dimensional
variable time using
      
        start1d = (/ 1,           timestep /)
        cnt1d   = (/ 12,                 1 /)

        status=nf_put_vara_int(ncid, timid, start1d, cnt1d, 
     &     timestep)

Since you're only writing one value, you could instead use
nf_put_var1_int with fewer arguments, but to use nf_put_vara this
should instead be
      
        start1d = (/ timestep /)
        cnt1d   = (/ 1 /)

        status=nf_put_vara_int(ncid, timid, start1d, cnt1d, 
     &     timestep)
        ! instead could have used
        ! status=nf_put_var1_int(ncid, timid, (/ timestep /),
     timestep)

For writing the 2D emis data into the appropriate time slab of the 3D
netCDF variable identified by emisid, it looks to me like you've got
it right!

        start2d = (/ 1,    1,         timestep /)
        cnt2d   = (/ 180,  360,              1 /)
      
        ! write 2d data: emissions 
        CALL nf(nf_put_vara_double(ncid, emisid, start2d, cnt2d, emis)) ! emis.

Just as an aside, you don't need to pass netCDF constants such as
nf_global, nf_float, etc. to a subroutine.  Instead, just use the
statement

   include 'netcdf.inc'   ! for Fortran 77
or
   use 'netcdf"           ! for Fortran 90

in the subroutine declarations, and all those parameter constants are
available from the appropriate include file or module file installed
with netCDF Fortran.

--Russ

> -----Original Message-----
> From: Unidata netCDF Support [mailto:address@hidden]
> Sent: maandag 14 oktober 2013 19:09
> To: Ganzeveld, Laurens
> Cc: address@hidden
> Subject: [netCDF #NUC-119714]: struggling with writing data to nc file
> 
> Laurens,
> 
> In order to understand what your code is intended to do, we will need for you 
> to send the output from running the following command:
> 
> ncdump -h /data/ganzevl/inputdata/emissions/EDGARV3.2/co_2000.nc
> 
> I suspect there might be a confusion of Fortran array order (first index 
> varying fastest) with C and CDL array order (last index varying fastest).
> 
> Also, since you are only using the netCDF-3 F77 functions, it might be easier 
> and less confusing for you to look at the older documentation for that 
> version of the F77 library, which is here (in HTML, or PDF, or
> ASCII):
> 
> http://www.unidata.ucar.edu/software/netcdf/old_docs/docs_3_6_3/netcdf-f77.html
> http://www.unidata.ucar.edu/software/netcdf/old_docs/docs_3_6_3/netcdf-f77.pdf
> http://www.unidata.ucar.edu/software/netcdf/old_docs/docs_3_6_3/netcdf-f77.txt
> 
> That's the documentation I'll refer to in discussing how to use 
> nf_get_vara_real
> from:
> 
> http://www.unidata.ucar.edu/netcdf/old_docs/docs_3_6_3/netcdf-f77.html#NF_005fGET_005fVARA_005f-type
> 
> for example.
> 
> --Russ
> 
> > Dear Unidata employees,
> >
> > I hope that you are actually working at the moment and not affected by
> > the government shutdown; I am already struggling now for some weeks
> > with a simple script to read and write data to netcdf in a F77 model
> > code. I am able to read-in and then write some manipulated data in F90
> > version but the F77 version gives problems with the writing; I have
> > copied below the F90 version of the write_nc routine I used and that
> > works with my installation of the netcdf software (3.6.2) on my
> > Suse11.2 linux system. I have also copied a version of the F77
> > subroutine that doesn't work; I am basically looking for the F77
> > equivalent of some of the calls of the various nc functions where the
> > help page has helped a lot but not to solve this remaining problem.
> > Your feedback would be highly appreciated,
> >
> > Thanks, Laurens Ganzeveld
> >
> > F90:
> >
> > The subroutine is called in a timeloop over 12 months writing out the
> > global emission field (emis3D), at a resolution of 1x1 degree for each
> > month to a new netcdf file:
> >
> > SUBROUTINE write_nc_file
> >
> > ! write timestep
> > CALL nf(nf90_inquire_dimension(ncid, tid, len=timestep)) timestep =
> > timestep + 1
> >
> > print *,'write_nc: timestepping ',timestep read (*,*)
> >
> > CALL nf(nf90_put_var(ncid, tid, time, (/timestep/) ))
> >
> > ! syntax: nf90_put_var(ncid, varid, values, start, cnt) ! start:
> > start in netcdf variable
> > ! cnt:    number of netcdf variable points
> > ! values: starting point of the fortran variable
> > start1d = (/ 1,               timestep /)
> > start2d = (/ 1,    1,         timestep /)
> > start3d = (/ 1,    1,   1,    timestep /)
> >
> > CALL nf(nf90_put_var(ncid, emis3Did,      emis3D,   start3d, cnt3d)) ! emis.
> >
> > END SUBROUTINE write_nc_file
> >
> >
> > F77:
> > Ncid, tid, emisid are all properly defined as well as the parameter
> > emis
> >
> > SUBROUTINE write_nc_file(ii,time,ncid,tid,emisid,emis)
> >
> > integer :: ii,timestep,status,ncid,tid,dimtid,timelen,nrecs,
> > &             emisid,start2d(3),cnt2d(3),j,k
> > real    :: time,emis(180,360)
> >
> > character*(20) recnam
> >
> > ! write timestep
> > timestep = ii
> > print *,'timestep',timestep,time
> >
> > CALL nf(nf_put_var_double(ncid, tid, time, (/timestep/) )) read (*,*)
> >
> > ! syntax: nf90_put_var(ncid, varid, values, start, cnt) ! start:
> > start in netcdf variable
> > ! cnt:    number of netcdf variable points
> > ! values: starting point of the fortran variable
> > start2d = (/ 1,    1,         timestep /)
> > cnt2d   = (/ 180,  360,              1 /)
> >
> > ! write 2d data
> >
> > CALL nf(nf_put_var_real(ncid, emisid, emis, start2d, cnt2d)) ! emis .
> >
> > END SUBROUTINE write_nc_file
> >
> > ======================================================================
> > =
> > Dr. ir. Laurens Ganzeveld
> > Assistant professor
> > Department of Environmental Sciences, Chair group Earth System
> > Sciences Wageningen University and Research Centre Lumen, room D.001,
> > Droevendaalsesteeg 4, 6708 PB, Wageningen, Netherlands
> > Phone: (+31) 317-486651 / 613066079, Fax: (+31) 317-419000, Being in
> > in Colombia: +57 310 2979313
> > E-mail: address@hidden<mailto:address@hidden>
> >
> > Affiliate of Universidad de Los Andes, Depart de Biología, Bogota,
> > Colombia Affiliate of Max Planck Institute for Chemistry, Depart. of
> > Atmospheric Chemistry, Mainz, Germany,
> > ======================================================================
> > =
> >
> >
> >
> Russ Rew                                         UCAR Unidata Program
> address@hidden                      http://www.unidata.ucar.edu
> 
> 
> 
> Ticket Details
> ===================
> Ticket ID: NUC-119714
> Department: Support netCDF
> Priority: Normal
> Status: Closed
> 
> 
> 

Russ Rew                                         UCAR Unidata Program
address@hidden                      http://www.unidata.ucar.edu



Ticket Details
===================
Ticket ID: NUC-119714
Department: Support netCDF
Priority: Normal
Status: Closed